As the sources of metal ore bodies such as copper ore bodies which can be usefully mined in an open pit or underground mine become less and less exploitable, as leaner deposits must be worked in order to provide increasing needs of metals, the deeper deposits become prime candidates as sources of copper. These deeper deposits have not been mined because of economic considerations. However, these deposits have become outstanding candidates for in-situ recovery such as in-situ leaching. The deeper deposits thus are suggested for working by in-situ mining techniques without the environmental problems, associated with solid state waste disposal and air pollution which may be avoided but an unavoidable with conventional technology.
Although copper oxide ore bodies and sulfidic copper ore bodies have been mined by in-situ leaching of an oxide or a sulfide mineral from a body fractured by bulk caving or conventional explosives preparatory to in-situ leaching (e.g., U.S. Pat. Nos. 2,563,623 and 3,640,579 and 3,574,599), the utilization of deposits in which the ratio of pyrite to chalcopyrite is low present a number heretofore unappreciated considerations.